It is well known that in underground mines fire constitutes an ever-present life-threatening hazard to workers. Fires endanger valuable lives of workers and also cause considerable economic losses to the mine operators. Fires occur because of the presence of combustible materials and the use of various mining equipment and techniques, open flames, blasting operations, inadvertent explosions, the use of electricity, the occurrence of friction between various elements, the occurrence of spontaneous combustion, and other possibilities. The product of fires generates smoke and carbon monoxide, both of which are life threatening to workers. It is well known that mine workers carry emergency gear such as oxygen equipment which must be immediately activated in the event of a hazardous situation, and that the workers must evacuate their stations to go to the nearest shelter or refuge bay having life-support equipment and supplies.
It is also well known that the normal life of oxygen equipment carried by a person is about 25 to 30 minutes, but inasmuch as a worker would have a very short time to reach the refuge bay the adrenalin generated in the body due to anxiety substantially reduces the normal life of oxygen equipment.
Additionally, very thick smoke associated with the fire reduces visibility to substantially zero and walking in complete darkness can cause a person to lose orientation as to the correct direction to take to reach a refuge bay before depleting the emergency equipment oxygen supply.
Heretofore, the common practice of evacuating a work station such as the face area in a coal mine would be to follow a conveyer in a passage until reaching a turning point of a branch going to a refuge bay. The turning point would normally be indicated in the form of a brick wall, a rope, or other suitable structure.
If a path along a conveyer run is blocked, another safe way to the refuge bay would be through a return airway or ventilating passage.
Thus, the most significant obstacle facing mine safety management during substantially zero visibility due to thick smoke is providing the workers with a safe and reliable method of reaching the nearest refuge bay in the shortest possible time to preserve their lives.
Heretofore, it has been known to provide guiding ropes and sequential alarm systems for guiding workers to a refuge bay. However, these systems have not proven to be completely safe and reliable primarily because in substantially zero visibility conditions orientation for proceeding to the nearest refuge bay may be lost causing an undue amount of time to safely reach the refuge bay. It has been known that many lives have been lost due to the fact that workers could not find the refuge bay in a timely fashion because of thick smoke and loss of orientation. The present invention overcomes these problems to provide a safe and reliable system for directing workers from a work station to a refuge bay in the shortest possible time.